VIRILE SENTIMENT 51 



Let me now proceed to describe one interesting 

 case, to show how false is this doctrine of environ- 

 ment, before I pass on to the second main purpose of 

 my address, i.e., to demonstrate the irrevocableness 

 and inevitableness of the transmission from generation 

 to generation of those inherent quahties that are, for 

 all practical purposes, the sole determining cause of 

 what an organism will be and do. In the Tyrolese 

 valleys and elsewhere there grow two plants known 

 as the Summer Savory and the Flax. In the valleys 

 both these plants are green in colour. This green 

 colour is due to a substance called chlorophyll, 

 and one of its inherent qualities is that it can 

 only exist as chlorophyll within a certain range 

 of light-intensity. In a too dull light it is not formed, 

 and in a too intense light it is destroyed. But this 

 chlorophyll is necessary for the existence of the 

 plant ; in its absence death ensues. Now, as we 

 move higher up a mountain the sunlight becomes 

 more intense, because there is a less thick layer 

 of atmosphere, with its contained water particles, 

 to absorb a certain measure of it. Consequently 

 at a certain height the light-intensity will be sufficient 

 to destroy the chlorophyll and kill the plant. The 

 hypothesis of this modern sentiment demands that 

 these two plants, placed under the same environment, 

 shall behave in the same way. For, assuredly, if 

 it is environment which determines the qualities or 

 behaviour of organisms, then the same environment 

 shall produce the same response in all organisms 

 subjected to its influence. If this be not the as- 



